JPH08224645A - Device that supplies steel to continuous casting mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the number of long-term service years of an apparatus for supplying steel from the bottom outlet of an intermediate vessel for continuous casting. SOLUTION: The intermediate vessel 2 for the apparatus for supplying the steel from the bottom outlet of the intermediate vessel 2 of continuous casting equipment is provided with an outlet block 3. A first change-over part 6 which is movable across a discharge direction 4 is arranged under the outlet block 3. A casting position can be pushed out by a moving device 30 and a second change-over part 38. The change-over parts 6 are assembled by a holding frame 12 and a casting nozzle object 11. The holding frame 12 is guided and positioned by a guiding band 11 in guide rails 7 and 7'. The holding frame 12 in a casting position is connected to a gas circulating system 17 and the gas inlet aperture 21 of the guide band 14 is located in a gas supply aperture 22 of the guide rail 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a device for feeding steel from a bottom outlet of an intermediate container to a continuous casting mold according to the preamble of claim 1.

[0002]

It is known to supply molten steel from an intermediate container to one or more continuous casting molds. With small cross-section villettes, it is possible to feed steel from an open bottom outlet without a sliding valve or stopper control directly on the mold. The service life of the refractory lining of the intermediate container is generally determined by the service life of the bottom outlet in continuous casting. If the continuous casting equipment is damaged during continuous casting, such as a breakout, the open bottom outlet can be closed with a copper stopper. Re-opening cannot avoid avoiding an unsatisfactory flow formation as it damages the nozzle block as the explosion is carried out using an oxygen lance.

In order to overcome the aforementioned drawbacks, stoppers or sliding valve controls are provided at the outlet nozzles of continuous casting equipment for billet and bloom cross sections. The enclosure for the exit block consisting of a slider plate is DE-
It is shown in the preamble of claim 1 of AP 1299804. Open guide rails are placed on either side of the outlet block to guide the slider plate across the discharge direction, and by a movable fixture that is firmly fixed around the casting vessel,
The first slider plate is extruded from the casting position, and
The second slider plate is moved to the casting position.

The production of such a slider plate with a length and width corresponding to 5 to 10 times the diameter of the casting nozzle is inexpensive. The large sliding surface that forms the slider surface with respect to the exit block needs to be highly accurately ground. When such slider plates are reduced, the slider surfaces heat up their metal plate shells, slide guides and their suspension means together, making them impractical after a relatively short time. Furthermore, the displacement path of this plate is inaccurate in length and does not result in a satisfactory match between the orifice of the outlet block and the outlet opening of the slider plate. Either of the proposed processes to limit the sliding movement is that the slider plate has to move before pushing back the old plate and has to be reinserted while positioning the new plate. I'm not satisfied.

[0005]

The object of the present invention relates to a device for feeding steel from the bottom outlet of an intermediate container to a continuous casting mold, in order to overcome the abovementioned drawbacks, in particular ensuring a long service life, And guarantee cheap production. However, the device for feeding the steel must have increased reliability during interruptions and must be capable of reliable restarting and casting at different extrusion speeds during continuous casting. A further aim is to increase the positioning accuracy between the orifice of the outlet block of the intermediate container and the insertion position of the casting nozzle body.

[0006]

According to the invention, this object is achieved by all the features of claim 1. The use of a movable casting nozzle allows a fast enclosure of the outlet opening of the intermediate container and re-opening with some emergency and difficult situations. Furthermore, the casting nozzles can be repositioned if, for a long period of continuous casting, a very large flow is produced due to wear or if plugging begins due to the deposition of aluminum oxide. With a high power continuous casting machine operating at substantially higher casting speeds after the initial casting period, the casting capacity can be readily adapted to the required casting parameters immediately by changing the casting nozzle.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Air-cooling of a holding frame enables a significant reduction of casting nozzle bodies, as well as an inexpensive production of casting nozzles with precise dimensional tolerances. The use of automatic casting nozzles helps optimize the utilization of the intermediate vessel, thus contributing to lower prices and increased capacity of continuous casting equipment.

The compressed gas supply may be connected to a compressed air network. If it is necessary to simultaneously block the casting flow, the gas circulation system can be connected to a nitrogen or inert gas source instead of compressed gas. The mobile device for inserting the switching element can be firmly fixed to a control panel connected to the casting vessel. In order to achieve precise alignment of the switching parts, especially without regard to the expansion associated with the uncontrolled casting vessel,
It has been proposed according to an embodiment that the guide rails, their suspension means and the mobile device are fixed to the bottom plate. The bottom plate can be designed to be easily attached and detached from the intermediate container.

The guide between the holding frame and the guide rail is designed as a simple sliding guide. According to a further embodiment, it is proposed that the guide band slides on the grooved guide track and that the gas supply opening opens into the groove.
The length of the groove of the guide band is about twice the length of the holding frame. This ensures the introduction of the second holding frame. The substantially right-angled or square-shaped holding frame has in the center a frustoconical receiving opening for a frustoconical casting nozzle object. Due to the circular shape of the casting nozzle body, the smallest possible annular sealing surface is formed between the casting nozzle body and the outlet block. The width of this annular sealing surface is, according to a preferred embodiment, 0.
5 to 1.5 times.

When shielding the surface of the casting stream and liquid from atmospheric oxygen during casting, a sealing ring for the bellows surrounds the guide rail of the bottom plate and a piston-cylinder arrangement is a switching part inside the sealing ring. Fixed to the bottom plate as a mobile device for. The sealing ring can be provided with a reinforcing projection with an orifice for the piston rod of the piston-cylinder device. In the rest position, the piston rod seals the orifice in the stiffening boss against entry of air into the space shielded by the bellows. An additional inlet / outlet pipe of the gas circulation system can be arranged on the reinforcing projection to cool the holding frame.

The bellows are usually fixed to the mold base and pressed against the upper sealing ring by means of a lifting device. If the holding frame is cooled with a protective gas, this cooling gas can be used as a preheated protective gas in the bellows after cooling the holding frame. The mobile for the switching part can remain in its operating position during casting. According to another embodiment, in order to ensure unobstructed access and free field of view for the insertion of the switching part in the guide, the mobile device for the switching part is parallel to the axis of movement of the switching part on the lever. It is hung in a slanted manner on a simple axis and can swivel around an axis between a rest position and an operating position.

The invention will be further described below with reference to the drawings.

[0013]

1 and 4 show an example of an arrangement for feeding steel from the bottom outlet, in which the intermediate container is shown simply by embedding the outlet block 3. Arrow 4
The discharge direction of the cast metal is shown. The switching part 6 is arranged at the casting position. The open guide rails 7 and 7'are elastically connected to the bottom plate 10 by screws 8 and springs 9, either on the side of this switching piece 6 or on the side of the outlet block 3.

The switching part 6 has a holding frame 12 made of steel for supporting the casting nozzle part 11. Holding frame 12
Is a guide strip 1 guided in the grooves 15 of the guide rails 7 and 7 '.
4 is provided. The guide strips 14 or the casting nozzles facing the outlet block 3 require guide rails 7 and 7'that exert an elastic compression force, so that they are elastically fixed to the bottom plate 10.

As further clearly shown in FIG. 2, the guide strip 7 is connected by a gas supply pipe 17 to the symbolic gas circulation system. The gas is supplied from the gas supply pipe 17 to the groove 15 via the orifice 18, and cools the holding frame 12 via the guide band 14. When the holding frame 12 is in the casting position, the gas outlet opening 22 of the guide band is
It coincides with the gas inlet opening 21 of the guide rail. The cooling gas flows through the cooling grooves 23 in the holding frame 12 and releases the gas to the opposite side via the guide rail 7 '. In this example, a protective gas, such as nitrogen or an inert gas, flows into the space enclosed by bellows 31. The bellows 31 can be sealed with respect to the intermediate container, so that the sealing ring 20 surrounding the guide rails 7 and 7'is clamped to the bottom plate 10. A piston-cylinder device 30, which is provided as a movable device for the switching piece outside the sealing ring 20, is flanged to the bottom plate 10. The piston rod 32 of the piston-cylinder device 30 is arranged in the orifice 33 in the reinforcing protrusion 34 of the sealing ring 20. In the rest position, the piston rod 32 seals the orifice 33 of the reinforcing projection against the entry of air into the space shielded by the bellows 31. Gas supply and exhaust pipes 36 (FIG. 4) of the gas circulation system can be arranged on the reinforcing projections 34 to cool the holding frame 12.

The conventionally known bellows 31 shown only in FIGS. 1 and 3 are firmly fixed to the mold table and can be lifted up and down to the sealing ring with a device. When the antioxidant gas is used as the cooling gas, the cooling gas is discharged into the bellows 31 after performing the cooling function. The entire switching device is arranged on the bottom plate 10 and can be easily attached to or detached from the bottom of the intermediate container by screws or wedges. A frustoconical guide 37 for centering and height positioning of the outlet block 3 is provided in the bottom plate 10.

The casting nozzle portion 11 or the blocking block 38
For the correct positioning of the cutting cone, a truncated cone-shaped casting nozzle part 11 or a frusto-conical receiving part 39 for the blocking block is attached to the holding frames 12 and 12 '. The ratio of the diameter of the nozzle orifice to the height of the casting nozzle is 1: 2 to 1: 5, preferably 1: 3 to.
When it is 1: 4, the service life of the casting nozzle part 11 is
It can be extended. The casting nozzle object relevant to the present invention is such that the discharge orifice is a few cm above the surface of the liquid in the mold.
Alternatively, it can be extended by dipping in a liquid.

The sealing surface between the outlet block 3 and the casting nozzle part 11 is annular and can be machined as a high-precision sealing surface with little expense. The width of the annular surface is 0.5 to 2 times, preferably 1 to 1.5 times the average nozzle orifice. In order to block the flow openings, a holding frame without the frustoconical receiving part 39 can be inserted, and the flow block can be made from steel or gray cast iron with an accompanying or separate enclosure. The holding frame is made up of. Also, this type of holding frame can be connected to a gas circulation system and is used repeatedly.

In FIG. 5, the same reference numerals as in FIGS. 1 to 3 are used for the same parts. In contrast to FIG. 3, a mobile device, which is designed similar to the piston-cylinder device 30, pivots from its working position 56 to its rest position 55. For this purpose, the lever 52 is swingably suspended on a shaft 50 arranged parallel to the movement axis 51 of the switching piece 6. The piston-cylinder device 30 is tightly fastened to this lever 52. If a new switching part is located below the casting outlet, the bellows 31 will be lowered in order to cross the open guide rails 7 and 7 '. After the manual introduction of the new switching element 6 into the open guide rails 7 and 7 ', the lever 52 with the piston-cylinder arrangement 40 pivots into the working position 56, just before the switching element 6 is replaced, as indicated by the dashed line. And fixing device 5
Fixed by 7. After replacing the old switching part 6 with a new switching part, the piston-cylinder arrangement 40 pivots backwards to the rest position and the bellows 34 is returned to the sealing position. The swivel axis 50 is a bellows 31.
Is advantageously located outside the.

Depending on the local space conditions, a vertical axis can be provided instead of the horizontal sub-axis 50 for pivoting the piston-cylinder arrangement 40.

[Brief description of drawings]

FIG. 1 is a longitudinal section through the bottom outlet of an intermediate container.

FIG. 2 is a cross section taken along line II-II in FIG.

FIG. 3 is a cross section taken along line III-III in FIG.

FIG. 4 is a cross section taken along line IV-IV in FIG.

FIG. 5 is an elevation and cross section of a suspension means for the movable arrangement of the switching parts.

[Explanation of symbols]

 2 ... Intermediate container 3 ... Exit block 4 ... Discharge direction 6 ... Switching part 7, 7 '... Open guide rail 8 ... Screw or suspension means 9 ... Spring 10 ... Bottom plate 11 ... Casting nozzle object 12, 12' ... Holding frame 14 ... Guide band 15 ... Groove 17 ... Gas supply pipe or circulation system 18 ... Orifice 20 ... Sealing ring 21 ... Gas inlet opening 22 ... Gas outlet opening 23 ... Cooling groove 30 ... Piston-cylinder device or movable device 31 ... Bellows 32 ... Piston rod 33 ... Orifice 34 ... Reinforcing protrusion 36 ... Supply and discharge pipe 37 ... Frustum-conical guide 38 ... Shielding block 39 ... Frustum-shaped receiving opening 40 ... Sealing surface 50 ... Swivel axis 51 ... Motion axis 52 ... Lever 55 ... Rest position 56 ... Working position 57 ... Fixing device

Claims (16)

[Claims] 1. An outlet block (3) for the intermediate container (2).
A first switching part (6) is provided below said outlet block (3) and is movable across the discharge direction (4).
Are installed on open guide rails (7, 7 ') located on both sides of the outlet block (3) in the casting position, and the switching part (6) is pushed out of the casting position by the movable device and the second switching part. This switching part is a device for feeding steel from a bottom outlet of an intermediate container to a continuous casting mold, which can be moved to a casting position, said switching part (6) being a refractory casting nozzle object (1
1) and the guide rails (7,
For the casting nozzle body (11), which has a guide band (14) for 7 ') and which is guided and positioned so that the casting nozzle body (11) is in close contact with the outlet block (3) Holding frame (12), and said holding frame (12) is connected to said holding frame cooling gas circulation system (17), said holding frame (12) of said guide band (14). The gas inlet opening (21) corresponds to the corresponding gas supply opening and gas discharge opening of the guide rail (7) in the casting position, and at least one of the guide rails is connected to the pressurized gas supply machine. An apparatus for supplying steel to a continuous casting mold, which is characterized by being. 2. The guide rail (7, 7 ′) loads the guide band (14) or the casting nozzle body (11) with a force that elastically compresses in the direction of the outlet block (3). The apparatus of claim 1, wherein 3. The guide rail (7, 7 '), the suspension means (8) of the guide rail, and the movable device (30),
Device according to claims 1 and 2, characterized in that it is fastened to a bottom plate (10) which can be attached to and removed from the intermediate container (2). 4. A sealing ring (20) for a bellows (31) is provided on a guide rail (7, 7) of said bottom plate (10).
7 ') surrounding said sealing ring (20)
Device according to claim 3, characterized in that on the outside of the, a piston-cylinder device is fastened to the bottom plate (10), which serves as a moving device for the switching piece (6). 5. The sealing ring (20) has a reinforcing projection (34) having an orifice (33) for the piston rod (32) of the piston-cylinder arrangement (30) and in the rest position, 5. The orifice (33) in the reinforcing projection (34) is sealed by the piston rod (32) to prevent atmospheric air from entering the space shielded by the bellows (31). Equipment. 6. The supply and discharge line (36) for the gas circulation system is arranged in a reinforcing projection (34) to cool the holding frame (12). And the device according to 5. 7. The bottom plate (10) has frustoconical guides (37) for centering and height positioning of the outlet block (3).
The apparatus according to any one of 1. 8. The gas circulation system is connected to a nitrogen or inert gas supply machine.
8. The device according to any one of 1 to 7. 9. A bellows (31) having a lifting device is provided between the sealing ring (20) and the mold table.
Device according to any one of claims 4 to 8, characterized in that the hot cooling gas in the bellows (31) leaves the gas circulation system. 10. The guide rail (7, 7 ′) has a groove-shaped guide track, and the gas supply opening is open to the groove (15). The apparatus according to any one of 1 to 9. 11. The holding frame (12, 12 ') is a frustoconical casting nozzle body (11) or a blocking block (3).
8) has a frustoconical receiving opening (39), and a cooling groove (23) has said receiving opening (39).
11. A device according to any one of claims 1 to 10, characterized in that it extends concentrically with. 12. Device according to claims 10 and 11, characterized in that the length of the groove (15) of the guide rail corresponds to twice the length of the holding frame (12). 13. The device according to claim 1, wherein the height of the casting nozzle body (11) corresponds to at least three times the diameter of the nozzle orifice. 14. Device according to claim 1, characterized in that the sealing surface (40) of the casting nozzle (11) facing the block (3) is annular. 15. Device according to claim 14, characterized in that the width of the annular sealing surface (40) is 0.5 to 1.5 times the average nozzle orifice. 16. A mobile device for the switching element (6) is provided on the lever (52) on the switching element (6).
Oscillatingly suspended on an axis (50) parallel to the movement axis (51) of the and pivoting about an axis (50) between the rest position (55) and the working position (56). Device according to any one of claims 1 to 15, characterized.